This invention relates generally to a bath waste and overflow system and more particularly to an improved valve control linkage having a ratchet construction that facilitates length adjustment of the linkage.
Drainage from bath tubs is commonly controlled by what is known in the plumbing industry as a trip lever bath waste and overflow. The plumbing in this type of system includes a drain ell which extends horizontally from the bottom drain port of the tub. The end wall of the tub has an elevated overflow port from which an overflow ell extends downwardly. The drain and overflow ells are connected by a T fitting which also provides a valve seat for a valve which is known as a drop cylinder. The drop cylinder is carried on a linkage which typically takes the form of two brass rods and a clevis. A trip lever mounted on the overflow plate on the end wall of the tub is manipulated to actuate the linkage and raise and lower the drop cylinder between open and closed positions to control the tub drainage.
Because bath tubs are not standardized, installation of the drainage system requires that the overflow ell be telescopically fitted in the top end of the T fitting and adjusted to accommodate the dimensions and construction of the tub. Consequently, the length of the valve control linkage must be variable in order to allow the drop cylinder to be properly seated and unseated when the system is installed on different styles of tubs. Conventionally, this length adjustment of the linkage is made possible by providing a threaded connection between the upper brass rod and the clevis. Even though this construction allows the linkage to be varied in its length, it is by no means an easy task to adjust the linkage so that it is exactly the proper length for each different installation. Adjustment can take several trial and error attempts and can require special trips to the installation site by the plumber. It can easily be appreciated that this can amount to substantial labor costs.
U.S. Pat. No. 4,352,213 to Watts makes reference to these problems and discloses a linkage adjustment system that allows the linkage to be quickly, easily and accurately adjusted. The present invention provides a different linkage construction which is equally, if not more easily, installed in the proper manner.
It is the principal goal of the invention to provide a linkage adjustment mechanism which allows the bath waste and overflow linkage to be accurately adjusted after it has been placed in the overflow tube assembly. By virtue of the ratchet construction that is provided on the linkage, the linkage can be inserted and then adjusted simply by operating the trip lever. This automatically retracts the linkage to the proper length, and the one way nature of the ratchet mechanism thereafter maintains it at the length required to achieve proper valving action of the drop cylinder.